The invention relates to a closure sequence control mechanism for a pair of turnable doors.
In order to lock a pair of doors to each other one of the door leaves is provided preferably with a latch bolt. As a consequence the door leaves must be closed in a certain order so that the door leaf provided with the latch bolt (hereinafter referred to as the second door leaf) is closed after the door leaf without the latch bolt (the first door leaf). The spring-loaded latch bolt then can be pressed, due to its bevelled guiding surface, into a lock housing in the second door leaf as the second door leaf is turned to its fully closed position. In this position the latch bolt can again move, urged by the spring, in to its protruding position, in which it locks the door leaves to each other. One closure sequence control mechanism suitable for the purpose is disclosed in the publication EP 0 458 034. This known solution is, however, constructionally complicated and the installation thereof is rather cumbersome.
An aim of the invention is to provide a closure sequence controller for a pair of turnable doors which ensures a desired order for the closing of the door leaves but which is constructionally simple and operationally reliable and which is further easy to install.
A further aim of the invention is to provide a closure sequence controller for a pair of doors which allows easy adaptation to door openings of different widths, and particularly to a substantially narrower door opening.
In accordance with the invention the blocking member is arranged in a guiding passage in the support element so that in its blocking position the blocking member extends partly out from the guiding passage into the path of movement of the end of the swing arm of the second door leaf. By means of this arrangement it can be ensured in a simple and reliable way that the first door leaf is closed before closing of the second door leaf.
In a favorable embodiment of the invention the support element has a guiding surface, which extends in the direction of the guide member and at which the guiding passage opens. The end of the control member at the side of the support element comprises with advantage a guiding element provided with a holder member, which cooperates with the guide member and with the guiding surface of the support element. When the door leaves are open the holder member is arranged, under the influence of the spring, at the position of the guiding passage to prevent movement of the blocking member to its releasing position.
Further the guiding element may have a guiding surface parallel with the guiding surface of the support element and located at a distance from it and allowing movement of the blocking member into its releasing position but preventing, however, movement of the blocking member completely out of the guiding passage.
The holder member comprises with advantage a separate spring-loaded holder piece. A construction of this kind serves as an overload clutch, which protects the mechanism from being damaged for instance in case of misuse. The force affecting the door leaf and releasing the clutch is then dependent on the strength of the spring in the clutch.
The control member can with advantage comprise an elongated arm member, which is detachably, for instance by threads, mounted at its ends on the one hand to the guiding element and on the other hand to a counter piece, which is arranged in cooperation with the end of the swing arm of the door closer of the first door leaf. Such an arrangement is constructionally simple and allows the effective length of the arm member to be adjusted, so that the closure sequence controller can be applied to door openings of different widths. The closure sequence controller can be applied to substantially narrower pairs of doors when necessary by shortening the arm member, for instance through truncation.
In practice the blocking member is with advantage a ball.